// SPDX-License-Identifier: GPL-2.0

  /****************************************************************************/
  /*
   *  linux/fs/binfmt_flat.c
   *
   *	Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
   *	Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
   *	Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
   *	Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
   *  based heavily on:
   *
   *  linux/fs/binfmt_aout.c:
   *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
   *  linux/fs/binfmt_flat.c for 2.0 kernel
   *	    Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
   *	JAN/99 -- coded full program relocation (gerg@snapgear.com)
   */

  #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

  #include <linux/kernel.h>
  #include <linux/sched.h>

  #include <linux/sched/task_stack.h>

  #include <linux/mm.h>
  #include <linux/mman.h>

  #include <linux/errno.h>
  #include <linux/signal.h>
  #include <linux/string.h>
  #include <linux/fs.h>
  #include <linux/file.h>

  #include <linux/ptrace.h>
  #include <linux/user.h>
  #include <linux/slab.h>
  #include <linux/binfmts.h>
  #include <linux/personality.h>
  #include <linux/init.h>
  #include <linux/flat.h>

  #include <linux/uaccess.h>

  #include <linux/vmalloc.h>

  
  #include <asm/byteorder.h>

  #include <asm/unaligned.h>
  #include <asm/cacheflush.h>

  #include <asm/page.h>

  
  /****************************************************************************/

  /*

   * User data (data section and bss) needs to be aligned.
   * We pick 0x20 here because it is the max value elf2flt has always
   * used in producing FLAT files, and because it seems to be large
   * enough to make all the gcc alignment related tests happy.
   */
  #define FLAT_DATA_ALIGN	(0x20)
  
  /*
   * User data (stack) also needs to be aligned.
   * Here we can be a bit looser than the data sections since this
   * needs to only meet arch ABI requirements.

   */

  #define FLAT_STACK_ALIGN	max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)

  #define RELOC_FAILED 0xff00ff01		/* Relocation incorrect somewhere */
  #define UNLOADED_LIB 0x7ff000ff		/* Placeholder for unused library */
  
  struct lib_info {
  	struct {
  		unsigned long start_code;		/* Start of text segment */
  		unsigned long start_data;		/* Start of data segment */
  		unsigned long start_brk;		/* End of data segment */
  		unsigned long text_len;			/* Length of text segment */
  		unsigned long entry;			/* Start address for this module */
  		unsigned long build_date;		/* When this one was compiled */

  		bool loaded;				/* Has this library been loaded? */

  	} lib_list[MAX_SHARED_LIBS];
  };
  
  #ifdef CONFIG_BINFMT_SHARED_FLAT
  static int load_flat_shared_library(int id, struct lib_info *p);
  #endif

  static int load_flat_binary(struct linux_binprm *);

  static int flat_core_dump(struct coredump_params *cprm);

  static struct linux_binfmt flat_format = {
  	.module		= THIS_MODULE,
  	.load_binary	= load_flat_binary,
  	.core_dump	= flat_core_dump,
  	.min_coredump	= PAGE_SIZE
  };
  
  /****************************************************************************/
  /*
   * Routine writes a core dump image in the current directory.
   * Currently only a stub-function.
   */

  static int flat_core_dump(struct coredump_params *cprm)

  {

  	pr_warn("Process %s:%d received signr %d and should have core dumped
  ",
  		current->comm, current->pid, cprm->siginfo->si_signo);

  	return 1;

  }
  
  /****************************************************************************/
  /*
   * create_flat_tables() parses the env- and arg-strings in new user
   * memory and creates the pointer tables from them, and puts their

   * addresses on the "stack", recording the new stack pointer value.

   */

  static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)

  {

  	char __user *p;
  	unsigned long __user *sp;
  	long i, len;

  	p = (char __user *)arg_start;
  	sp = (unsigned long __user *)current->mm->start_stack;
  
  	sp -= bprm->envc + 1;
  	sp -= bprm->argc + 1;
  	sp -= flat_argvp_envp_on_stack() ? 2 : 0;
  	sp -= 1;  /* &argc */
  
  	current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
  	sp = (unsigned long __user *)current->mm->start_stack;
  
  	__put_user(bprm->argc, sp++);

  	if (flat_argvp_envp_on_stack()) {

  		unsigned long argv, envp;
  		argv = (unsigned long)(sp + 2);
  		envp = (unsigned long)(sp + 2 + bprm->argc + 1);
  		__put_user(argv, sp++);
  		__put_user(envp, sp++);
  	}
  
  	current->mm->arg_start = (unsigned long)p;
  	for (i = bprm->argc; i > 0; i--) {
  		__put_user((unsigned long)p, sp++);
  		len = strnlen_user(p, MAX_ARG_STRLEN);
  		if (!len || len > MAX_ARG_STRLEN)
  			return -EINVAL;
  		p += len;
  	}
  	__put_user(0, sp++);
  	current->mm->arg_end = (unsigned long)p;
  
  	current->mm->env_start = (unsigned long) p;
  	for (i = bprm->envc; i > 0; i--) {
  		__put_user((unsigned long)p, sp++);
  		len = strnlen_user(p, MAX_ARG_STRLEN);
  		if (!len || len > MAX_ARG_STRLEN)
  			return -EINVAL;
  		p += len;
  	}
  	__put_user(0, sp++);
  	current->mm->env_end = (unsigned long)p;
  
  	return 0;

  }
  
  /****************************************************************************/
  
  #ifdef CONFIG_BINFMT_ZFLAT
  
  #include <linux/zlib.h>
  
  #define LBUFSIZE	4000
  
  /* gzip flag byte */
  #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
  #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
  #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
  #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
  #define COMMENT      0x10 /* bit 4 set: file comment present */
  #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
  #define RESERVED     0xC0 /* bit 6,7:   reserved */

  static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
  		long len, int fd)

  {
  	unsigned char *buf;
  	z_stream strm;

  	int ret, retval;

  	pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)
  ", fpos, dst, len);

  
  	memset(&strm, 0, sizeof(strm));
  	strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);

  	if (!strm.workspace)

  		return -ENOMEM;

  	buf = kmalloc(LBUFSIZE, GFP_KERNEL);

  	if (!buf) {

  		retval = -ENOMEM;
  		goto out_free;
  	}
  
  	/* Read in first chunk of data and parse gzip header. */

  	ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);

  
  	strm.next_in = buf;
  	strm.avail_in = ret;
  	strm.total_in = 0;
  
  	retval = -ENOEXEC;
  
  	/* Check minimum size -- gzip header */
  	if (ret < 10) {

  		pr_debug("file too small?
  ");

  		goto out_free_buf;
  	}
  
  	/* Check gzip magic number */
  	if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {

  		pr_debug("unknown compression magic?
  ");

  		goto out_free_buf;
  	}
  
  	/* Check gzip method */
  	if (buf[2] != 8) {

  		pr_debug("unknown compression method?
  ");

  		goto out_free_buf;
  	}
  	/* Check gzip flags */
  	if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
  	    (buf[3] & RESERVED)) {

  		pr_debug("unknown flags?
  ");

  		goto out_free_buf;
  	}
  
  	ret = 10;
  	if (buf[3] & EXTRA_FIELD) {
  		ret += 2 + buf[10] + (buf[11] << 8);

  		if (unlikely(ret >= LBUFSIZE)) {

  			pr_debug("buffer overflow (EXTRA)?
  ");

  			goto out_free_buf;
  		}
  	}
  	if (buf[3] & ORIG_NAME) {

  		while (ret < LBUFSIZE && buf[ret++] != 0)

  			;

  		if (unlikely(ret == LBUFSIZE)) {

  			pr_debug("buffer overflow (ORIG_NAME)?
  ");

  			goto out_free_buf;
  		}
  	}
  	if (buf[3] & COMMENT) {

  		while (ret < LBUFSIZE && buf[ret++] != 0)

  			;

  		if (unlikely(ret == LBUFSIZE)) {

  			pr_debug("buffer overflow (COMMENT)?
  ");

  			goto out_free_buf;
  		}
  	}
  
  	strm.next_in += ret;
  	strm.avail_in -= ret;
  
  	strm.next_out = dst;
  	strm.avail_out = len;
  	strm.total_out = 0;
  
  	if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {

  		pr_debug("zlib init failed?
  ");

  		goto out_free_buf;
  	}
  
  	while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {

  		ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);

  		if (ret <= 0)
  			break;

  		len -= ret;
  
  		strm.next_in = buf;
  		strm.avail_in = ret;
  		strm.total_in = 0;
  	}
  
  	if (ret < 0) {

  		pr_debug("decompression failed (%d), %s
  ",

  			ret, strm.msg);
  		goto out_zlib;
  	}
  
  	retval = 0;
  out_zlib:
  	zlib_inflateEnd(&strm);
  out_free_buf:
  	kfree(buf);
  out_free:
  	kfree(strm.workspace);

  	return retval;
  }
  
  #endif /* CONFIG_BINFMT_ZFLAT */
  
  /****************************************************************************/
  
  static unsigned long
  calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
  {
  	unsigned long addr;
  	int id;
  	unsigned long start_brk;
  	unsigned long start_data;
  	unsigned long text_len;
  	unsigned long start_code;
  
  #ifdef CONFIG_BINFMT_SHARED_FLAT
  	if (r == 0)
  		id = curid;	/* Relocs of 0 are always self referring */
  	else {
  		id = (r >> 24) & 0xff;	/* Find ID for this reloc */
  		r &= 0x00ffffff;	/* Trim ID off here */
  	}
  	if (id >= MAX_SHARED_LIBS) {

  		pr_err("reference 0x%lx to shared library %d", r, id);

  		goto failed;
  	}
  	if (curid != id) {
  		if (internalp) {

  			pr_err("reloc address 0x%lx not in same module "
  			       "(%d != %d)", r, curid, id);

  			goto failed;

  		} else if (!p->lib_list[id].loaded &&
  			   load_flat_shared_library(id, p) < 0) {

  			pr_err("failed to load library %d", id);

  			goto failed;
  		}
  		/* Check versioning information (i.e. time stamps) */
  		if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
  				p->lib_list[curid].build_date < p->lib_list[id].build_date) {

  			pr_err("library %d is younger than %d", id, curid);

  			goto failed;
  		}
  	}
  #else
  	id = 0;
  #endif
  
  	start_brk = p->lib_list[id].start_brk;
  	start_data = p->lib_list[id].start_data;
  	start_code = p->lib_list[id].start_code;
  	text_len = p->lib_list[id].text_len;
  
  	if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {

  		pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",

  		       r, start_brk-start_data+text_len, text_len);

  		goto failed;
  	}
  
  	if (r < text_len)			/* In text segment */
  		addr = r + start_code;
  	else					/* In data segment */
  		addr = r - text_len + start_data;
  
  	/* Range checked already above so doing the range tests is redundant...*/

  	return addr;

  
  failed:

  	pr_cont(", killing %s!
  ", current->comm);

  	send_sig(SIGSEGV, current, 0);
  
  	return RELOC_FAILED;
  }
  
  /****************************************************************************/

  static void old_reloc(unsigned long rl)

  {

  	static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };

  	flat_v2_reloc_t	r;

  	unsigned long __user *ptr;
  	unsigned long val;

  	r.value = rl;
  #if defined(CONFIG_COLDFIRE)

  	ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);

  #else

  	ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);

  #endif

  	get_user(val, ptr);

  	pr_debug("Relocation of variable at DATASEG+%x "
  		 "(address %p, currently %lx) into segment %s
  ",

  		 r.reloc.offset, ptr, val, segment[r.reloc.type]);

  	switch (r.reloc.type) {
  	case OLD_FLAT_RELOC_TYPE_TEXT:

  		val += current->mm->start_code;

  		break;
  	case OLD_FLAT_RELOC_TYPE_DATA:

  		val += current->mm->start_data;

  		break;
  	case OLD_FLAT_RELOC_TYPE_BSS:

  		val += current->mm->end_data;

  		break;
  	default:

  		pr_err("Unknown relocation type=%x
  ", r.reloc.type);

  		break;
  	}

  	put_user(val, ptr);

  	pr_debug("Relocation became %lx
  ", val);

  }

  
  /****************************************************************************/

  static int load_flat_file(struct linux_binprm *bprm,

  		struct lib_info *libinfo, int id, unsigned long *extra_stack)
  {

  	struct flat_hdr *hdr;
  	unsigned long textpos, datapos, realdatastart;

  	u32 text_len, data_len, bss_len, stack_len, full_data, flags;

  	unsigned long len, memp, memp_size, extra, rlim;

  	u32 __user *reloc, *rp;

  	struct inode *inode;

  	int i, rev, relocs;

  	loff_t fpos;
  	unsigned long start_code, end_code;

  	ssize_t result;

  	int ret;

  
  	hdr = ((struct flat_hdr *) bprm->buf);		/* exec-header */

  	inode = file_inode(bprm->file);

  
  	text_len  = ntohl(hdr->data_start);
  	data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
  	bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
  	stack_len = ntohl(hdr->stack_size);
  	if (extra_stack) {
  		stack_len += *extra_stack;
  		*extra_stack = stack_len;
  	}
  	relocs    = ntohl(hdr->reloc_count);
  	flags     = ntohl(hdr->flags);
  	rev       = ntohl(hdr->rev);

  	full_data = data_len + relocs * sizeof(unsigned long);

  	if (strncmp(hdr->magic, "bFLT", 4)) {

  		/*

  		 * Previously, here was a printk to tell people
  		 *   "BINFMT_FLAT: bad header magic".
  		 * But for the kernel which also use ELF FD-PIC format, this
  		 * error message is confusing.

  		 * because a lot of people do not manage to produce good

  		 */

  		ret = -ENOEXEC;
  		goto err;

  	}
  
  	if (flags & FLAT_FLAG_KTRACE)

  		pr_info("Loading file: %s
  ", bprm->filename);

  
  	if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {

  		pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)
  ",
  		       rev, FLAT_VERSION, OLD_FLAT_VERSION);

  		ret = -ENOEXEC;
  		goto err;

  	}

  	/* Don't allow old format executables to use shared libraries */
  	if (rev == OLD_FLAT_VERSION && id != 0) {

  		pr_err("shared libraries are not available before rev 0x%lx
  ",
  		       FLAT_VERSION);

  		ret = -ENOEXEC;
  		goto err;

  	}
  
  	/*

  	 * Make sure the header params are sane.
  	 * 28 bits (256 MB) is way more than reasonable in this case.
  	 * If some top bits are set we have probable binary corruption.
  	*/
  	if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
  		pr_err("bad header
  ");
  		ret = -ENOEXEC;
  		goto err;
  	}
  
  	/*

  	 * fix up the flags for the older format,  there were all kinds
  	 * of endian hacks,  this only works for the simple cases
  	 */
  	if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
  		flags = FLAT_FLAG_RAM;
  
  #ifndef CONFIG_BINFMT_ZFLAT
  	if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {

  		pr_err("Support for ZFLAT executables is not enabled.
  ");

  		ret = -ENOEXEC;
  		goto err;

  	}
  #endif
  
  	/*
  	 * Check initial limits. This avoids letting people circumvent
  	 * size limits imposed on them by creating programs with large
  	 * arrays in the data or bss.
  	 */

  	rlim = rlimit(RLIMIT_DATA);

  	if (rlim >= RLIM_INFINITY)
  		rlim = ~0;

  	if (data_len + bss_len > rlim) {
  		ret = -ENOMEM;
  		goto err;
  	}

  	/* Flush all traces of the currently running executable */
  	if (id == 0) {

  		ret = flush_old_exec(bprm);
  		if (ret)

  			goto err;

  
  		/* OK, This is the point of no return */

  		set_personality(PER_LINUX_32BIT);

  		setup_new_exec(bprm);

  	}
  
  	/*
  	 * calculate the extra space we need to map in
  	 */

  	extra = max_t(unsigned long, bss_len + stack_len,
  			relocs * sizeof(unsigned long));

  
  	/*
  	 * there are a couple of cases here,  the separate code/data
  	 * case,  and then the fully copied to RAM case which lumps
  	 * it all together.
  	 */

  	if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {

  		/*
  		 * this should give us a ROM ptr,  but if it doesn't we don't
  		 * really care
  		 */

  		pr_debug("ROM mapping of file (we hope)
  ");

  		textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,

  				  MAP_PRIVATE|MAP_EXECUTABLE, 0);

  		if (!textpos || IS_ERR_VALUE(textpos)) {

  			ret = textpos;

  			if (!textpos)
  				ret = -ENOMEM;

  			pr_err("Unable to mmap process text, errno %d
  ", ret);

  			goto err;

  		}

  		len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);

  		len = PAGE_ALIGN(len);

  		realdatastart = vm_mmap(NULL, 0, len,

  			PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);

  		if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {

  			ret = realdatastart;

  			if (!realdatastart)

  				ret = -ENOMEM;

  			pr_err("Unable to allocate RAM for process data, "

  			       "errno %d
  ", ret);

  			vm_munmap(textpos, text_len);

  			goto err;

  		}

  		datapos = ALIGN(realdatastart +
  				MAX_SHARED_LIBS * sizeof(unsigned long),
  				FLAT_DATA_ALIGN);

  		pr_debug("Allocated data+bss+stack (%u bytes): %lx
  ",

  			 data_len + bss_len + stack_len, datapos);

  
  		fpos = ntohl(hdr->data_start);
  #ifdef CONFIG_BINFMT_ZFLAT
  		if (flags & FLAT_FLAG_GZDATA) {

  			result = decompress_exec(bprm, fpos, (char *)datapos,

  						 full_data, 0);

  		} else
  #endif
  		{

  			result = read_code(bprm->file, datapos, fpos,
  					full_data);

  		}

  		if (IS_ERR_VALUE(result)) {

  			ret = result;

  			pr_err("Unable to read data+bss, errno %d
  ", ret);

  			vm_munmap(textpos, text_len);
  			vm_munmap(realdatastart, len);

  			goto err;

  		}

  		reloc = (u32 __user *)

  			(datapos + (ntohl(hdr->reloc_start) - text_len));

  		memp = realdatastart;

  		memp_size = len;

  	} else {

  		len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);

  		len = PAGE_ALIGN(len);

  		textpos = vm_mmap(NULL, 0, len,

  			PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);

  		if (!textpos || IS_ERR_VALUE(textpos)) {

  			ret = textpos;

  			if (!textpos)
  				ret = -ENOMEM;

  			pr_err("Unable to allocate RAM for process text/data, "

  			       "errno %d
  ", ret);

  			goto err;

  		}
  
  		realdatastart = textpos + ntohl(hdr->data_start);

  		datapos = ALIGN(realdatastart +

  				MAX_SHARED_LIBS * sizeof(u32),

  				FLAT_DATA_ALIGN);

  		reloc = (u32 __user *)

  			(datapos + (ntohl(hdr->reloc_start) - text_len));

  		memp = textpos;

  		memp_size = len;

  #ifdef CONFIG_BINFMT_ZFLAT
  		/*
  		 * load it all in and treat it like a RAM load from now on
  		 */
  		if (flags & FLAT_FLAG_GZIP) {

  #ifndef CONFIG_MMU

  			result = decompress_exec(bprm, sizeof(struct flat_hdr),
  					 (((char *)textpos) + sizeof(struct flat_hdr)),

  					 (text_len + full_data

  						  - sizeof(struct flat_hdr)),

  					 0);
  			memmove((void *) datapos, (void *) realdatastart,

  					full_data);

  #else
  			/*
  			 * This is used on MMU systems mainly for testing.
  			 * Let's use a kernel buffer to simplify things.
  			 */
  			long unz_text_len = text_len - sizeof(struct flat_hdr);
  			long unz_len = unz_text_len + full_data;
  			char *unz_data = vmalloc(unz_len);
  			if (!unz_data) {
  				result = -ENOMEM;
  			} else {
  				result = decompress_exec(bprm, sizeof(struct flat_hdr),
  							 unz_data, unz_len, 0);
  				if (result == 0 &&
  				    (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
  						  unz_data, unz_text_len) ||
  				     copy_to_user((void __user *)datapos,
  						  unz_data + unz_text_len, full_data)))
  					result = -EFAULT;
  				vfree(unz_data);
  			}
  #endif

  		} else if (flags & FLAT_FLAG_GZDATA) {

  			result = read_code(bprm->file, textpos, 0, text_len);

  			if (!IS_ERR_VALUE(result)) {
  #ifndef CONFIG_MMU

  				result = decompress_exec(bprm, text_len, (char *) datapos,

  						 full_data, 0);

  #else
  				char *unz_data = vmalloc(full_data);
  				if (!unz_data) {
  					result = -ENOMEM;
  				} else {
  					result = decompress_exec(bprm, text_len,
  						       unz_data, full_data, 0);
  					if (result == 0 &&
  					    copy_to_user((void __user *)datapos,
  							 unz_data, full_data))
  						result = -EFAULT;
  					vfree(unz_data);
  				}

  #endif

  			}
  		} else
  #endif /* CONFIG_BINFMT_ZFLAT */

  		{

  			result = read_code(bprm->file, textpos, 0, text_len);
  			if (!IS_ERR_VALUE(result))
  				result = read_code(bprm->file, datapos,
  						   ntohl(hdr->data_start),
  						   full_data);

  		}

  		if (IS_ERR_VALUE(result)) {

  			ret = result;

  			pr_err("Unable to read code+data+bss, errno %d
  ", ret);

  			vm_munmap(textpos, text_len + data_len + extra +

  				MAX_SHARED_LIBS * sizeof(u32));

  			goto err;

  		}
  	}

  	start_code = textpos + sizeof(struct flat_hdr);
  	end_code = textpos + text_len;
  	text_len -= sizeof(struct flat_hdr); /* the real code len */

  
  	/* The main program needs a little extra setup in the task structure */

  	if (id == 0) {
  		current->mm->start_code = start_code;
  		current->mm->end_code = end_code;
  		current->mm->start_data = datapos;
  		current->mm->end_data = datapos + data_len;
  		/*
  		 * set up the brk stuff, uses any slack left in data/bss/stack
  		 * allocation.  We put the brk after the bss (between the bss
  		 * and stack) like other platforms.

  		 * Userspace code relies on the stack pointer starting out at
  		 * an address right at the end of a page.

  		 */
  		current->mm->start_brk = datapos + data_len + bss_len;
  		current->mm->brk = (current->mm->start_brk + 3) & ~3;

  #ifndef CONFIG_MMU

  		current->mm->context.end_brk = memp + memp_size - stack_len;

  #endif

  	}

  	if (flags & FLAT_FLAG_KTRACE) {

  		pr_info("Mapping is %lx, Entry point is %x, data_start is %x
  ",
  			textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
  		pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx
  ",
  			id ? "Lib" : "Load", bprm->filename,
  			start_code, end_code, datapos, datapos + data_len,
  			datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);

  	}

  
  	/* Store the current module values into the global library structure */
  	libinfo->lib_list[id].start_code = start_code;
  	libinfo->lib_list[id].start_data = datapos;
  	libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
  	libinfo->lib_list[id].text_len = text_len;
  	libinfo->lib_list[id].loaded = 1;
  	libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
  	libinfo->lib_list[id].build_date = ntohl(hdr->build_date);

  	/*
  	 * We just load the allocations into some temporary memory to
  	 * help simplify all this mumbo jumbo
  	 *
  	 * We've got two different sections of relocation entries.

  	 * The first is the GOT which resides at the beginning of the data segment

  	 * and is terminated with a -1.  This one can be relocated in place.
  	 * The second is the extra relocation entries tacked after the image's
  	 * data segment. These require a little more processing as the entry is
  	 * really an offset into the image which contains an offset into the
  	 * image.
  	 */
  	if (flags & FLAT_FLAG_GOTPIC) {

  		for (rp = (u32 __user *)datapos; ; rp++) {
  			u32 addr, rp_val;

  			if (get_user(rp_val, rp))
  				return -EFAULT;
  			if (rp_val == 0xffffffff)
  				break;
  			if (rp_val) {
  				addr = calc_reloc(rp_val, libinfo, id, 0);

  				if (addr == RELOC_FAILED) {
  					ret = -ENOEXEC;

  					goto err;

  				}

  				if (put_user(addr, rp))
  					return -EFAULT;

  			}
  		}
  	}
  
  	/*
  	 * Now run through the relocation entries.
  	 * We've got to be careful here as C++ produces relocatable zero
  	 * entries in the constructor and destructor tables which are then
  	 * tested for being not zero (which will always occur unless we're
  	 * based from address zero).  This causes an endless loop as __start
  	 * is at zero.  The solution used is to not relocate zero addresses.
  	 * This has the negative side effect of not allowing a global data
  	 * reference to be statically initialised to _stext (I've moved
  	 * __start to address 4 so that is okay).
  	 */
  	if (rev > OLD_FLAT_VERSION) {

  		u32 __maybe_unused persistent = 0;

  		for (i = 0; i < relocs; i++) {

  			u32 addr, relval;

  			/*
  			 * Get the address of the pointer to be
  			 * relocated (of course, the address has to be
  			 * relocated first).
  			 */

  			if (get_user(relval, reloc + i))
  				return -EFAULT;
  			relval = ntohl(relval);

  			if (flat_set_persistent(relval, &persistent))

  				continue;

  			addr = flat_get_relocate_addr(relval);

  			rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
  			if (rp == (u32 __user *)RELOC_FAILED) {

  				ret = -ENOEXEC;

  				goto err;

  			}

  
  			/* Get the pointer's value.  */

  			ret = flat_get_addr_from_rp(rp, relval, flags,
  							&addr, &persistent);
  			if (unlikely(ret))
  				goto err;

  			if (addr != 0) {
  				/*
  				 * Do the relocation.  PIC relocs in the data section are
  				 * already in target order
  				 */
  				if ((flags & FLAT_FLAG_GOTPIC) == 0)
  					addr = ntohl(addr);
  				addr = calc_reloc(addr, libinfo, id, 0);

  				if (addr == RELOC_FAILED) {
  					ret = -ENOEXEC;

  					goto err;

  				}

  
  				/* Write back the relocated pointer.  */

  				ret = flat_put_addr_at_rp(rp, addr, relval);
  				if (unlikely(ret))
  					goto err;

  			}
  		}
  	} else {

  		for (i = 0; i < relocs; i++) {

  			u32 relval;

  			if (get_user(relval, reloc + i))
  				return -EFAULT;
  			relval = ntohl(relval);
  			old_reloc(relval);
  		}

  	}

  	flush_icache_range(start_code, end_code);
  
  	/* zero the BSS,  BRK and stack areas */

  	if (clear_user((void __user *)(datapos + data_len), bss_len +
  		       (memp + memp_size - stack_len -		/* end brk */
  		       libinfo->lib_list[id].start_brk) +	/* start brk */
  		       stack_len))
  		return -EFAULT;

  
  	return 0;

  err:
  	return ret;

  }
  
  
  /****************************************************************************/
  #ifdef CONFIG_BINFMT_SHARED_FLAT
  
  /*
   * Load a shared library into memory.  The library gets its own data
   * segment (including bss) but not argv/argc/environ.
   */
  
  static int load_flat_shared_library(int id, struct lib_info *libs)
  {
  	struct linux_binprm bprm;
  	int res;
  	char buf[16];

  	memset(&bprm, 0, sizeof(bprm));

  	/* Create the file name */
  	sprintf(buf, "/lib/lib%d.so", id);
  
  	/* Open the file up */
  	bprm.filename = buf;
  	bprm.file = open_exec(bprm.filename);
  	res = PTR_ERR(bprm.file);
  	if (IS_ERR(bprm.file))
  		return res;

  	bprm.cred = prepare_exec_creds();
  	res = -ENOMEM;
  	if (!bprm.cred)
  		goto out;

  	/* We don't really care about recalculating credentials at this point
  	 * as we're past the point of no return and are dealing with shared
  	 * libraries.
  	 */

  	bprm.called_set_creds = 1;

  	res = prepare_binprm(&bprm);

  	if (!res)

  		res = load_flat_file(&bprm, libs, id, NULL);

  
  	abort_creds(bprm.cred);
  
  out:
  	allow_write_access(bprm.file);
  	fput(bprm.file);

  	return res;

  }
  
  #endif /* CONFIG_BINFMT_SHARED_FLAT */
  /****************************************************************************/
  
  /*
   * These are the functions used to load flat style executables and shared
   * libraries.  There is no binary dependent code anywhere else.
   */

  static int load_flat_binary(struct linux_binprm *bprm)

  {
  	struct lib_info libinfo;

  	struct pt_regs *regs = current_pt_regs();

  	unsigned long stack_len = 0;

  	unsigned long start_addr;

  	int res;
  	int i, j;
  
  	memset(&libinfo, 0, sizeof(libinfo));

  	/*
  	 * We have to add the size of our arguments to our stack size
  	 * otherwise it's too easy for users to create stack overflows
  	 * by passing in a huge argument list.  And yes,  we have to be
  	 * pedantic and include space for the argv/envp array as it may have
  	 * a lot of entries.
  	 */

  #ifndef CONFIG_MMU
  	stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
  #endif

  	stack_len += (bprm->argc + 1) * sizeof(char *);   /* the argv array */
  	stack_len += (bprm->envc + 1) * sizeof(char *);   /* the envp array */
  	stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);

  	res = load_flat_file(bprm, &libinfo, 0, &stack_len);

  	if (res < 0)

  		return res;

  	/* Update data segment pointers for all libraries */

  	for (i = 0; i < MAX_SHARED_LIBS; i++) {
  		if (!libinfo.lib_list[i].loaded)
  			continue;
  		for (j = 0; j < MAX_SHARED_LIBS; j++) {
  			unsigned long val = libinfo.lib_list[j].loaded ?
  				libinfo.lib_list[j].start_data : UNLOADED_LIB;
  			unsigned long __user *p = (unsigned long __user *)
  				libinfo.lib_list[i].start_data;
  			p -= j + 1;
  			if (put_user(val, p))
  				return -EFAULT;
  		}
  	}

  	install_exec_creds(bprm);

  
  	set_binfmt(&flat_format);

  #ifdef CONFIG_MMU
  	res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
  	if (!res)
  		res = create_flat_tables(bprm, bprm->p);
  #else

  	/* Stash our initial stack pointer into the mm structure */
  	current->mm->start_stack =
  		((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
  	pr_debug("sp=%lx
  ", current->mm->start_stack);

  	/* copy the arg pages onto the stack */

  	res = transfer_args_to_stack(bprm, &current->mm->start_stack);
  	if (!res)
  		res = create_flat_tables(bprm, current->mm->start_stack);

  #endif

  	if (res)
  		return res;

  	/* Fake some return addresses to ensure the call chain will
  	 * initialise library in order for us.  We are required to call
  	 * lib 1 first, then 2, ... and finally the main program (id 0).
  	 */
  	start_addr = libinfo.lib_list[0].entry;
  
  #ifdef CONFIG_BINFMT_SHARED_FLAT

  	for (i = MAX_SHARED_LIBS-1; i > 0; i--) {

  		if (libinfo.lib_list[i].loaded) {
  			/* Push previos first to call address */

  			unsigned long __user *sp;
  			current->mm->start_stack -= sizeof(unsigned long);
  			sp = (unsigned long __user *)current->mm->start_stack;
  			__put_user(start_addr, sp);

  			start_addr = libinfo.lib_list[i].entry;
  		}
  	}
  #endif

  #ifdef FLAT_PLAT_INIT
  	FLAT_PLAT_INIT(regs);
  #endif

  	pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)
  ",
  		 regs, start_addr, current->mm->start_stack);

  	start_thread(regs, start_addr, current->mm->start_stack);

  	return 0;
  }
  
  /****************************************************************************/
  
  static int __init init_flat_binfmt(void)
  {

  	register_binfmt(&flat_format);
  	return 0;

  }

  core_initcall(init_flat_binfmt);

  
  /****************************************************************************/